Here are a couple of TiVo "repair" sites:
http://www.tivofaq.com/hack/faq.html
http://www.9thtee.com/tivoupgrades.htm
I was going to open mine and work on the modem, but one it had more than one step, it was out of my realm.
I still have it - maybe one day I'll get bored and take it apart.
